Abstract: A process for classifying water-absorbing polymer particles, wherein screens having different mesh sizes are used before and after surface postcrosslinking to remove the undersize (fines).

Abstract: The invention relates to the production of superabsorbent polymers comprising conveying a polymer gel having acid groups on an oscillating conveyor belt to a continuous through-circulation belt dryer, wherein the belt speed of the conveyor belt is at least 0.4 m/s.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising polymerization, drying the resulting polymer gel on a through circulation belt dryer, crushing the dried polymer gel, pre-grinding, separating of incompletely dried particles with a perforated plate, grinding and classifying the resulting polymer particles.

Abstract: The present invention relates to a process for producing fluid-absorbent cores, comprising mixing a fibrous material and fluid-absorbent polymer particles having low moisture content and low apparent density and pressing the obtained mixture under specific conditions.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising the steps of: —processing an aqueous polymer gel from polymerization of a monomer solution or suspension, —drying the aqueous polymer gel in a conveyer dryer, in particular in a forced air conveyer dryer, wherein —the conveyer dryer has a circulating conveyer belt and the aqueous polymer gel is conveyed on the circulating conveyer belt, and wherein —the circulating conveyer belt is formed as a circulating plate conveyer belt, comprising a number of belt plates separated by a hinge line of a hinge assembly and each belt plate having a surface for receiving the aqueous polymer gel, wherein said hinge assembly comprises a knuckle joint (301) with the hinge line in form of a straight hinge line.

Abstract: The present invention relates to a fluid-absorbent article, comprising a water-absorbent core with a basis weight of the fluid-absorbent core at the insult zone of at least 500 gsm, comprising 10 to 100% by weight water-absorbent polymer particles, wherein the water-absorbent polymer particles having a mean sphericity (SPHT) from 0.8 to 0.95 and satisfying the following conditions: (a) the sum of centrifuge retention capacity (CRC) and absorbency under high load (AUHL) being at least 60 g/g, and/or (b) the log10(SFC)>5.7?0.138×CRC, with SFC being not less than 5, wherein the CRC is given in g/g and the SFC in 10?7 cm3?s/g.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising polymerization and drying the resulting polymer gel on a through-circulation belt dryer having at the end of the belt in transport direction a means for guiding the dried polymer gel down towards a means for crushing the dried polymer gel.

Abstract: A process for producing water-absorbing polymer particles, wherein surface postcrosslinked water-absorbing polymer particles are remoisturized and classified, and wherein the time between remoisturization and classification is at least 15 minutes.

Abstract: A process for continuously preparing water-absorbing polymer beads, comprising the drying of a polymer gel on a forced-air belt dryer, the water content of the polymer gel being used to control the forced-air belt dryer during or after the drying.

Abstract: A process for classifying water-absorbing polymer particles, wherein screens having different mesh sizes are used before and after surface postcrosslinking to remove the undersize (fines).

Abstract: A process for producing water-absorbing polymer particles by polymerizing an aqueous monomer solution in a polymerization reactor with at least two axially parallel rotating shafts, wherein the polymerization is performed in the presence of an inert gas and under positive pressure.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising polymerization and drying the resulting polymer gel on a through-circulation belt dryer having at the end of the belt in transport direction a means for guiding the dried polymer gel down towards a means for crushing the dried polymer gel.

Abstract: A process for producing water-absorbing polymer particles, comprising the steps of thermal cracking of bionaphtha in the presence of steam, removing propene and at least some of the propane, gas phase oxidation to give acrylic acid and polymerization to give water-absorbing polymer particles.

Abstract: A process for continuously producing water-absorbing polymer particles by polymerizing a monomer solution comprising acrylic acid and/or salts thereof, wherein the acrylic acid supplied has a dimeric acrylic acid content of at least 0.02% by weight and the dimeric acrylic acid content is kept essentially constant.

Abstract: The present invention relates to fluid-absorbent articles, comprising an upper liquid-pervious layer, a lower liquid-impervious layer and a fluid-absorbent core, wherein the fluid-absorbent core comprises a fibrous material and 10 to 95% by weight of spherical fluid-absorbent polymer particles having a moisture content of at least 8% by weight.

Abstract: The invention relates to a process for producing water-absorbing polymer particles, comprising thermal postcrosslinking in a contact dryer having external heated outer surfaces.

Abstract: A process for continuously producing water-absorbing polymer particles by polymerizing a monomer solution comprising acrylic acid and/or salts thereof, wherein the acrylic acid supplied has a dimeric acrylic acid content of at least 0.02% by weight and the dimeric acrylic acid content is kept essentially constant.

Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, wherein a water-insoluble inorganic salt is suspended in the monomer solution and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: The present invention relates to a process for producing fluid-absorbent cores, comprising mixing a fibrous material and fluid-absorbent polymer particles having low moisture content and low apparent density and pressing the obtained mixture under specific conditions.

Abstract: A process for classifying water-absorbing polymer beads, wherein the polymer beads are separated into n particle size fractions by means of at least n screens and n is an integer greater than 1.